<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>16、受控组件</title>
</head>
<body>
    <div id="test"></div>

    <script type="text/javascript" src="../js/react.development.js"></script>
    <script type="text/javascript" src="../js/react-dom.development.js"></script>
    <script type="text/javascript" src="../js/babel.min.js"></script>
    <!-- 对props属性类型，以及是否必传进行限制 -->
    <script type="text/javascript" src="../js/prop-types.js"></script>
    
    <script type="text/babel"> 
        class Login extends React.Component{
            // 受控组件即随着表单变动，将值维护到状态中
            state = {
                username: '',
                password: ''
            }
            render(){
                return (
                    <form onSubmit={this.handleSubmit}>
                        用户名：<input onChange={this.saveUsername} type="text" name="username" /><br />
                        密码：<input onChange={this.savePassword} type="password" name="password" /><br />
                        <button>登录</button>
                    </form>
                ) 
            }
            saveUsername = (event) => {
                this.setState({username: event.target.value})
            }
            savePassword = (event) => {
                this.setState({password: event.target.value})
            }
            handleSubmit = (event) => {
                event.preventDefault();
                const {username,password} = this.state
                alert(`你输入的用户名是：${username}，你输入的密码是：${password}`)
            }
        }
        ReactDOM.render(<Login />,document.getElementById('test'))
    </script>
</body>
</html>